forkmanagerフォーク（）関数は、このマシン上で実装されていません

Question

ルビーによって使用forkmanagerこの起こる.IT場合： ルビーバージョン： ルビーを2.4.1p111（2017年3月22日リビジョン58053）のx64-MINGW32] システムのバージョン： windows7 64 未知の例外：このマシンでfork（）関数が実装されていません D：/Ruby24-x64/lib/ruby/gems/2.4.0/gems/parallel-forkmanager-2.0.1/lib/parallel/forkmanager RB：525：fork' D:/Ruby24-x64/lib/ruby/gems/2.4.0/gems/parallel-forkmanager- 2.0.1/lib/parallel/forkmanager.rb:525:inスタート」

#!/usr/bin/env ruby 
#encoding: UTF-8 
# 抓取每一个站点的首页链接数量 

require 'rubygems'   
require 'ap'    
require 'json' 
require 'net/http' 
require 'nokogiri'   
require 'forkmanager'  
require 'beanstalk-client' 

class MultipleCrawler 

    class Crawler 
     def initialize(user_agent, redirect_limit=1) 
      @user_agent = user_agent 
      @redirect_limit = redirect_limit 
      @timeout = 20 
     end 
     attr_accessor :user_agent, :redirect_limit, :timeout 

     def fetch(website) 
      print "Pid:#{Process.pid}, fetch: #{website}\n" 
      redirect, url = @redirect_limit, website 
      start_time = Time.now 
      redirecting = false 
      begin 
       begin 
        uri = URI.parse(url) 
        req = Net::HTTP::Get.new(uri.path) 
        req.add_field('User-Agent', @user_agent) 
        res = Net::HTTP.start(uri.host, uri.port) do |http| 
         http.read_timeout = @timeout 
         http.request(req) 
        end 
        if res.header['location'] # 遇到重定向，则url设定为location，再次抓取 
         url = res.header['location'] 
         redirecting = true 
        end 
        redirect -= 1 
       end while redirecting and redirect>=0 
       opened_time = (Time.now - start_time).round(4) # 统计打开网站耗时 
       encoding = res.body.scan(/<meta.+?charset=["'\s]*([\w-]+)/i)[0] 
       encoding = encoding ? encoding[0].upcase : 'GB18030' 
       html = 'UTF-8'==encoding ? res.body : res.body.force_encoding('GB2312'==encoding || 'GBK'==encoding ? 'GB18030' : encoding).encode('UTF-8') 
       doc = Nokogiri::HTML(html) 
       processed_time = (Time.now - start_time - opened_time).round(4) # 统计分析链接耗时, 1.8.7, ('%.4f' % float).to_f 替换 round(4) 
       [opened_time, processed_time, doc.css('a[@href]').size, res.header['server']] 
      rescue =>e 
       e.message 
      end 
     end 
    end 

    def initialize(websites, beanstalk_jobs, pm_max=1, user_agent='', redirect_limit=1) 
     @websites = websites    # 网址数组 
     @beanstalk_jobs = beanstalk_jobs # beanstalk服务器地址和管道参数 
     @pm_max = pm_max     # 最大并行运行进程数 
     @user_agent = user_agent   # user_agent 伪装成浏览器访问 
     @redirect_limit = redirect_limit # 允许最大重定向次数 

     @ipc_reader, @ipc_writer = IO.pipe # 缓存结果的 ipc 管道 
    end 

    attr_accessor :user_agent, :redirect_limit 

    def init_beanstalk_jobs # 准备beanstalk任务 
     beanstalk = Beanstalk::Pool.new(*@beanstalk_jobs) 
     #清空beanstalk的残留消息队列 
     begin 
      while job = beanstalk.reserve(0.1) 
       job.delete 
      end 
     rescue Beanstalk::TimedOut 
      print "Beanstalk queues cleared!\n" 
     end 
     @websites.size.times{|i| beanstalk.put(i)} # 将所有的任务压栈 
     beanstalk.close 
     rescue => e 
      puts e 
      exit 
    end 

    def process_jobs # 处理任务 
     start_time = Time.now 
     pm = Parallel::ForkManager.new(@pm_max) 
     @pm_max.times do |i| 
      # 启动后，立刻 next 不会等待进程执行完，这样才可以并行运算 
      pm.start(i) and next 
      beanstalk = Beanstalk::Pool.new(*@beanstalk_jobs) 
      # 关闭读取管道，子进程只返回数据 
      @ipc_reader.close 
      loop{ 
       begin 
        # 检测超时为0.1秒，因为任务以前提前压栈 
        job = beanstalk.reserve(0.1) 
        index = job.body 
        job.delete 
        website = @websites[index.to_i] 
        result = Crawler.new(@user_agent).fetch(website) 
        @ipc_writer.puts(({website=>result}).to_json) 
       rescue Beanstalk::DeadlineSoonError, Beanstalk::TimedOut, SystemExit, Interrupt 
        break 
       end 
      } 
      @ipc_writer.close 
      pm.finish(0)  
     end 
     @ipc_writer.close 
     begin 
      # 等待所有子进程处理完毕 
      pm.wait_all_children 
      # 遇到中断，打印消息  
     rescue SystemExit, Interrupt  
      print "Interrupt wait all children!\n" 
     ensure 
      results = read_results 
      # 打印处理结果 
      ap results, :indent => -4 , :index=>false 
      print "Process end, total: #{@websites.size}, crawled: #{results.size}, time: #{'%.4f' % (Time.now - start_time)}s.\n" 
     end 
    end 

    def read_results # 通过管道读取子进程抓取返回的数据 
     results = {} 
     while result = @ipc_reader.gets 
      results.merge! JSON.parse(result) 
     end 
     @ipc_reader.close 
     results 
    end 

    def run # 运行入口 
     init_beanstalk_jobs 
     process_jobs 
    end 
end 

websites = %w(
http://www.51buy.com/ http://www.360buy.com/ http://www.tmall.com/ http://www.taobao.com/ 
http://china.alibaba.com/ http://www.paipai.com/ http://shop.qq.com/ http://www.lightinthebox.com/ 
http://www.amazon.cn/ http://www.newegg.com.cn/ http://www.vancl.com/ http://www.yihaodian.com/ 
http://www.dangdang.com/ http://www.m18.com/ http://www.suning.com/ http://www.hstyle.com/ 
) 

beanstalk_jobs = [['127.0.0.1:11300'],'crawler-jobs'] 
user_agent = 'Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/60.0.3112.113 Safari/537.36' 
pm_max = 10 

MultipleCrawler.new(websites, beanstalk_jobs, pm_max, user_agent).run 

Answer 1

にあなたは、Windows PC上でこれを実行しているように見えます。

forkは、POSIX/Unixシステムコールであるため、 POSIX/Unixシステムでのみ使用できます。

可能な解決策は、WindowsマシンでCygwynを使用することです。